Such telecommunication units are available, particularly in the form of telecommunication terminal units, such as portable computers or portable telephones or the like, which have a projection device.
Such communication units have the advantage that, for showing image information, not only a comparatively small display area, or rather display device of the telecommunication unit is available but, especially in the case in which several people have to look together at the image information shown, the functionality is made possible that the image information is projected onto a projection area that is located outside the telecommunication unit. In such a showing of an image or a film using a projection device, also designated as a beamer below, the control in stationary units is usually provided using remote operation and a corresponding menu control, the menu being typically displayed directly in the projected image. However, even in the case of the integration of a projection device into a typically portable telecommunication unit, the functionality is required that control elements and control data have to be transferred or transmitted to the unit.
In a projection device built into a portable telecommunication unit, this usually takes place in that the unit, particularly a touch-sensitive surface of the unit, or an input device such as a keyboard device, or the like, has to be touched (particularly by a finger of the user), which has the disadvantage, however, that a projected image is interfered with, in particular by wobbling or other negative effects. In addition, it is a disadvantage that on a telecommunication unit, especially a portable one, there is typically little space for input elements, such as control buttons or operating devices, and that the unit is frequently not positioned optimally, for the operation of the input elements by a user, when the projection device is used.